Pictures of the day: 23 October 2012

A new image of the Sun blurs the line between science and art. A Nasa scientist has used a technique known as a "gradient filter", similar to a photo-editing program, to highlight the places of greatest physical change. Scientists employed the filter to enhance contrast, using them to accentuate fine structures that might otherwise be lost in the background noise. It was used to study a phenomenon known as coronal loops, which are giant arcs of solar material constrained to travel along that particular path by the magnetic fields in the sun's atmosphere. Observations of the loops, which can be more or less tangled and complex during different phases of the sun's 11-year activity cycle, can help researchers understand what's happening with the sun's complex magnetic fields, fields that can also power great eruptions on the sun such as solar flares or coronal mass ejections.Picture: Nasa/Rex Features